I've been borrowing books from a library and suddenly something went wrong and I'm not able to borrow anything anymore. The downloading of a borrowed book starts normally and opens ADE, but the book doesn't show up in ADE. In library it shows that I have the book eventhough it's not shown in ADE.Now I'm trying to uninstall ADE, but it remembers my ID in reinstall. I tried another library but the same problem continues

Tried to use cmd+shift+D but nothing happens...

So how to remove ADE totally from a Mac or to deauthorise it when the suggested cmd+shift+D doesn't seem to work?